前言
###我做这类文章一个重要的目的还是给正在学习的大家提供方向（例如想要掌握基础用法，该刷哪些题？建议灵神的题单和代码随想录）和记录自己的学习过程，我的解析也不会做的非常详细，只会提供思路和一些关键点，力扣上的大佬们的题解质量是非常非常高滴！！！
习题
1.单值二叉树
题目链接:965. 单值二叉树 - 力扣（LeetCode）
题面:
代码:
/*** Definition for a binary tree node.* public class TreeNode {* int val;* TreeNode left;* TreeNode right;* TreeNode() {}* TreeNode(int val) { this.val = val; }* TreeNode(int val, TreeNode left, TreeNode right) {* this.val = val;* this.left = left;* this.right = right;* }* }*/
class Solution {Boolean ans = true;int flag = 0;public boolean isUnivalTree(TreeNode root) {flag = root.val;recursion(root);return ans;}public void recursion(TreeNode node){if(node==null||ans==false)return;if(node.val!=flag){ans = false;return;}recursion(node.left);recursion(node.right);}
}2.翻转等价二叉树
题目链接: 951. 翻转等价二叉树 - 力扣（LeetCode）
题面:
思路:模拟题目中求是否是等价二叉树的过程
代码:
/*** Definition for a binary tree node.* public class TreeNode {* int val;* TreeNode left;* TreeNode right;* TreeNode() {}* TreeNode(int val) { this.val = val; }* TreeNode(int val, TreeNode left, TreeNode right) {* this.val = val;* this.left = left;* this.right = right;* }* }*/
class Solution {Boolean ans = true;public boolean flipEquiv(TreeNode root1, TreeNode root2) {if((root1==null&&root2!=null)||(root1!=null&&root2==null))return false;recursion(root1,root2);return ans;}public void recursion(TreeNode node1,TreeNode node2){if(node1==null||ans==false)return;if(node1.val!=node2.val){ans = false;return;}if(node1.left!=null&&node1.right!=null){if(node2.left==null||node2.right==null){ans = false;return;}if(node2.left.val==node1.right.val&&node2.right.val==node1.left.val){reverse(node1);}else if(node1.left.val!=node2.left.val||node1.right.val!=node2.right.val){ans = false;return; }}else if(node1.left!=null){if((node2.left!=null&&node2.right!=null)||(node2.left==null&&node2.right==null)){ans = false;return;}int k = node1.left.val;if(node2.left!=null){if(k!=node2.left.val){ans = false;return;}}else{int r2 = node2.right.val;if(k==r2){reverse(node1);}else{ans = false;return;}}}else if(node1.right!=null){if((node2.left!=null&&node2.right!=null)||(node2.left==null&&node2.right==null)){ans = false;return;}int k = node1.right.val;if(node2.right!=null){if(k!=node2.right.val){ans = false;return;}}else{int r2 = node2.left.val;if(k==r2){reverse(node1);}else{ans = false;return;}}}else{if(node2.left!=null||node2.right!=null){ans = false;return;}}if(node1.left!=null){recursion(node1.left,node2.left); }if(node1.right!=null){recursion(node1.right,node2.right);}}public void reverse(TreeNode node){TreeNode left = node.left;TreeNode right = node.right;node.left = right;node.right = left;}
}后言
上面是数据结构相关的习题，下一篇文章会将其他相关的习题。
